I had been friends with a couple for about 4 years, when we were hanging out the wife and I were alone for a bit and as im sitting there she kneels at my feet and tells me they fantasized about the idea of her being with me and him watching and asked if I would be interested.
It was sort of out of the blue because they never brought it up and I was friends with them and didn't flirt with wife or anything although I knew she thought I was good looking and liked that I was a big guy, but not much more.
I was surprised and the way she asked was really cool. I think since they asked me they left it open as to what it would include, she got very submissive towards me and he followed that lead and we didn't really discuss details but since they had known me awhile they trusted me.
Next day we met at their place and she came in alone and kneeled at my feet again, and let me know he may sneak a peek later but she was here to make me happy. Was cute because she took my cock out and just played with it around her face and sucked on it, got her boobs out, we talked and played. I thought it was very hot because we had known each other awhile but now to spend time together on that level was exciting.
My cock was longer and thicker than his and she had not been with anyone else in a decade or so she was happy about that lol. After about 20 minutes alone I saw him peek from the other room in. you could see his eyes widen as he sees her mouth on my dick and then he went away again.
It ended up being a very fun time that evolved over a year, I did a lot of things with her that he never got to do so he was getting turned on seeing her like that. First couple times he just watched and her and I spent time together being intimate and playing. Was nice to develop that bond with a married woman. Then we did it some with him joining in etc. He did feel inadequate sometimes, so it was sexy to give his wife something he could not. we did it a number of times and that's when I learned I liked it :)